A Dose-ranging Study to Investigate Efficacy of Buntanetap in Mild to Moderate AD

320 mild to moderate AD participants will be randomized to 7.5 mg, 15 mg, 30mg of buntanetap/Posiphen once daily (QD) or placebo. If they provide informed consent, they will undergo a Screening Visit, and if they are considered eligible per the inclusion and exclusion criteria, they will proceed to participate in the treatment period. Randomized participants will visit the clinic for the first-time dosing in clinic, followed by an at home dosing period of 12 weeks, with daily administration of 7.5 mg, 15 mg or 30 mg of buntanetap/Posiphen or placebo. Participants will be required to visit clinics Day 0 (baseline), 6 weeks, and 12 weeks (end-of-trial), where they will undergo study procedures that include safety assessments (AE and concomitant medication monitoring, 12-lead ECGs, clinical laboratory testing, vital signs assessments, and physical examinations) and psychometric tests (Alzheimer's Disease Assessment Scale-Cognitive Subscale 11 (ADAS-Cog11), Alzheimer's Disease Cooperative Study-Clinical Global Impression of Change (ADCS-CGIC), Alzheimer's Disease Cooperative Study-Instrumental Activities of Daily Living Scale (ADCS-ADL), Digital Symbol Substitution Test (DSST), Mini Mental State Examination (MMSE)). At the end of blood sampling, the participants will need to stay for a minimum of 1 hour of observation. After all end-of-study procedures are complete, the subject will be discharged to home. A 24-hour follow-up call will occur after all clinical visits to assess the participants current condition and if there are any additional adverse events or questions. The study will be a 12-weeks, placebo-controlled and double-blind trial: participants, investigators and the sponsor will be blinded to the participants' treatment. Qualified participants will be randomly assigned at a 1:1:1:1 ratio to one of the four treatment arms: buntanetap/Posiphen 7.5 mg, buntanetap/Posiphen 15 mg, buntanetap/Posiphen 30mg, and placebo, through an Interactive Randomization System, after a screening period of up to 42 days. ADAS-Cog 11, ADCS-CGIC, ADCS-ADL, DSST, and MMSE will be assessed by clinicians who have successfully completed the requisite certifications/trainings for each assessment. One interim analysis is planned. It will take place when 90 enrolled subjects (\~30%) have completed the Week 6 assessments to re-assess the sample size. No interim analyses are planned for the purpose of stopping the study early for futility.